Mask washer



May 14, 1963 R. B. WAY ETAL 3,08

MASK WASHER Filed Sept. 29, 1960 3 Sheets-Sheet 1 FIG.)

INVENTOR- Roas B, WA) BY CARL D I 19 7 ATTORNEY May 14, 1963 R. B. WAY ETAL 3,089,499

MASK WASHER Filed Sept. 29, 1960 3 Sheets-Sheet 2 IN V EN TORS Foes/er 5. WAY BY /"1L, D HERSE) ATTORNEY May 14, 1963 R. B. WAY ETAL 3,089,499

MASK WASHER Filed Sept. 29, 1960 5 Sheets-Sheet 3 Ln o 8 a g Q a) 0: LI.

. f\ (4 L9 0 w M INVENTORS kaasxr 6. MY CARI. .0, Hsxscy BY 8M KZWVM RTTORNEV I assesses Patented May 14, 1963 3,089,499 MASK WASHER Robert B. Way, 1503 Chelsea Ave, and Carl D. Hersey, 3107 Marvin Ave., both of Erie, Pa. Filed Sept. 29, 1960, Ser. No. 59,279

7 Claims. (Cl. 134-441) This invention relates to painting machines and, more particularly, to machines for washing masks.

In removing the excess paint from masks and stencils used in spray painting operations, it is important to provide a machine which will thoroughly remove the excess paint in a minimum of time. Mask washing machines which will accomplish this purpose successfully have not been produced previously.

The machine disclosed herein moves the masks through the solvent solution at a relatively high Velocity. The movement or rotation of the mask is reversed periodically which causes an even greater relative velocity of fluid to wash and a greater flow of fluid over the mask and agitation of the fluid during the period of reversal. This results in additional mask cleaning. Since the masks are moved out of the fluid at the end of each cycle, the solvent will drain oif of the masks and the masks can be loaded and unloaded above the liquid level. The location of the parts of the machine makes them readily accessible for service, repair, and operation since the masks stop in a horizontal position. The toggle clamps disclosed make it possible to load and unload the mask washer rapidly. The screen at the bottom of the tank allows the sludge to separate from the solvent and protects the sludge from subsequent agitation and resultant contamination of the solvent. The air circuit which operates the machine renders the machine explosion proof.

The structure of the machine makes it possible to make the tank and mask support long enough to accommodate extremely long mask-s. The method disclosed works equally well with either large or small tanks since the mask is moved, not the fluid. Therefore, the mechanical problems of moving large quantities of fluid are eliminated. The machine uses no pumps, nozzles, or similar circulating devices ordinarily used. Therefore, the machine avoids the inherent difliculties usually encountered with such compoents.

The embodiment of the invention shown in FIG. 6 utilizes a simple harmonic motion to slow the movement of the mask down at the end of each stroke to prevent excessive splashing of liquid.

It is, accordingly, an object of the present invention to provide an improved mask washing machine.

Another object of the invention is to provide a mask cleaning machine in which the mask is moved relative to the fluid in the machine.

A further object of the invention is to provide a mask washing and cleaning machine which is simple in construction, economical to manufacture, and simple and eificient in operation.

With the above and other objects in view, the present invention consists of the combination and arrangement of parts hereinafter more fully described, illustrated in the accompanying drawings and more particularly pointed out in the appended claims, it being understood that changes may be made in the form, size, proportions, and minor details of construction without departing from the spirit or sacrificing any of the advantages of the invention.

In the drawings:

FIG. 1 is an end view of a invention;

FIG. 2 is a side view of the machine having a part of one side thereof broken away to show the internal parts;

machine according to the FIG. 3 is a cross sectional view taken on line 3-3 of FIG. 4;

FIG. 4 is a schematic pneumatic circuit of the machine;

FIG. 5 is an enlarged view of the clamp for the mask; and

FIG. 6 is a view of another embodiment of the invention.

Now with more specific reference 1 to 4 show a mask washer 10 generally made up of a tank, a mask holder, an air motor -12 to rotate the mask holder, and a pneumatic arrangement shown in the circuit to control the motor 12.

The mask holder is oscillated by a gear reducer 11 driven by the air motor 12. The air motor 12 is supplied with air from a filter 13 which supplies air through a check valve 14 and a lubricator 15. Each of the valves to the drawings, FIGS.

shown are provided with mufllers 16 for reducing the noise of the air therefrom.

The pneumatic circuit is made up of valves 17, 19, 20, 22, 23, 28 and 52. The valves 17, 1'9, and 28 are pilot operated valves which control the flow of air to the motor 12. The cam operated valves 22 and 52 have mechanically operated pilots thereon which are operated by a cam 25. The cam 25 is driven by the motor 12.

The timer valve 20 has a throttling valve 27 controlling its pilot orifice. The throttling valve 27 is connected from the valve to the atmosphere to allow air to escape from a bleed valve controlled by a knob 21 to determine the rate at which the air bleeds out of the pilot through the restricted orifice.

The motor 12 drives the gear reducer 11 through a shaft 47 which is connected by a flexible coupling 26 to a shaft 48. Air is supplied to start the motor 12 by the hand operated valve 23 which supplies air to the timer valve 20 through a line 63 and a cut-out valve 24.

The tank is supported on legs 33 which extend upwardly to form a right tank end 41 and a left tank end 42. The

tank has sides 52' and 53 which extend down and converge downwardly and inwardly to form bottom sections 54 and 55. The sides 52 and 53 and the bottom sections 54- and 55 are welded to the ends 41 and 42 to form a sealed tank. The sides 52 and 53 curve upwardly and over at the top to form smooth contoured corners 56 and 57. An opening 50 is formed at the top for the lid and is also provided for inserting and removing masks. The lower ends of the legs terminate in feet 49 which may rest on a floor or other supporting surface.

A mask holder 39 is preferably made of a structural member T-shaped in cross section and it is welded at its ends to a stub shaft 30 at one end and to a hub plate 31 at the other end. It will be noted that the mask holder 39 is supported eccentrically from the axes of rotation of shafts 30 and 58 so that when they rotate, the mask support swings through an arcuate path defined by the hub plates 31. The shaft 30 is welded to a cross bar or flange 59 of the T-shaped mask support at one end thereof.

The stub shaft 30 is supported in a bearing 29 which may be a non-friction bearing and is supported to the end of the tank by means of bolts 45. The bolts 45 extend through a plate 36 and a sealing gasket 37 to form a seal over the holes which receive the bolts 45. A seal 38 prevents leak-age through the bore which receives the shaft 30.

The shaft 58 extends through a bore in the other end of the tank and the bore is sealed against leakage by a seal 35. The shaft 58 extends outwardly and is connected to the driving mechanism of the gear reducer 11 whereby the shaft is driven.

The gear reducer 11 is supported on tank by means of bolts 43 to hold the in place and the shaft 58 is gripped by the end of the gear reducer 11 a hub 32 which is bolted to the hub plate 31. The bottom of the tank has a strainer 34 which is in the form of a perforated sheet of steel welded to the ends so that paint can settle from the solvent after the paint is removed from the masks. Paint will settle below the strainer 34 and, therefore, not be agitated by the rotation of the mask holder 39.

The cam 25 has a stop member 82 which moves with the cam and engages a stop bar 48 on the fixed end of the tank to prevent rotation of the cam beyond its intended range of rotation in case of malfunction of any of the operating valves.

In operation, a supply of compressed air is connected to the machine through a line 68 and it passes through the filter 13. Main air from the filter 13 passes into a line 62 to the hand actuated starting valve 23 which is normally closed. Air further passes through the check valve 14 and the lubricator 15 into a line 61 which leads to the valves 17, 28, 20, and 22, all of which are closed when the machine is at rest. The check valve 14 is inserted in the line to prevent oiled air from being forced back into the filter 13 when the machine is shut down.

The washing cycle is started by pressing a pilot member 23 of the starting valve 23. This action will open the valve 23, connecting the line 62 to the line 63, allowing air to pass through the cut-out valve 24 to a timer pilot cylinder 80 of the timer valve 20. The cut-out valve 24 is constructed so that it closes after passing a fixed amount of air, thus ensuring that an equal charge of air passes to the timer pilot cylinder 88 each time the starting valve 23 is actuated. This charge of air to the timer pilot cylinder 81 causes the timer valve to open, connecting the line 61 with a line 64.

Air in the line 64 opens the pilot opening valve 28. The opening valve 28 connects the line 61 with a line 65, passing air to a pilot cylinder 81 of the valve 17 which causes the valve 17 to open, then connecting line 61 with a line 66. The air from the line 66 passes through the valve 19 into a line 67 to the air motor 12. Passing air to the left port of the air motor will cause it to rotate and, through its shaft 47, the flexible coupling 26, and the gear reducer input shaft 48, rotate the gear reducer output shaft 58 in a clockwise direction. The shaft 58 is attached to the cam and the mask holder 39 and, therefore, the mask holder 39 carries the mask attached to it through the solution and it also moves the cam 25. The clockwise rotation will continue until a cam lobe 68 contacts a cam roller 69 of the valve 22, opening the valve 22. Opening the valve 22 connects the line 61 with a line 70, passing air to a pilot cylinder 71 of the four-way valve 19, shifting the valve 19 and thus connecting a line 67 to the exhaust port and connecting the line 66 with a line 72.

Air also flows from the line 72 to the valve 52 which is in a closed position at this time. Connecting the line 66 with the line 72 allows air to pass to the right hand port of the air motor 12, reversing the direction of the rotation of the motor and causing the cam 25 and the mask holder 39 to rotate in a counterclockwise direction. This counterclockwise rotation will continue until the cam lobe contacts a cam roller 77 of the valve 52, opening the valve. Opening the valve 52 connects the line 72 with a line 73, allowing air to pass to a pilot cylinder 74 of the valve 19, shifting the spool of the valve and, also, through a restrictor '75 to a pilot cylinder 76 of the valve 17.

Because full air pressure from the line 65 is acting against the pilot cylinder 81 of the valve 17, the reduced air pressure flowing through the restrictor 75 to the pilot cylinder 76 cannot move the spool of the valve 17 which, therefore, remains open. Shifting the spool of the valve 19 exhausts the line 72 and connects the line 66 with the line 67, directing air to the left port of the air motor 12 and reversing the motion of the cam 25 and the mask holder 39.

The reversing action continues until the timer valve 20 times out and .closes. This takes place when the initial charge of air from the cut-out valve 24 to the timer pilot cylinder 80 bleeds out of the throttling valve 27, allowing a spring 20A to close the valve 20. Closing the valve 20 exhausts the line 64 to the pilot cylinder of the valve 28, allowing the spring to close the valve 28. Closing the valve 28 also exhausts the line 65 to the pilot cylinder '81 of the valve 17. The next time that the valve 52 is opened by the cam 25, air flowing from the line 73 through the restrictor 75 to the pilot cylinder 76 will close the valve 17, shutting off the air supply to the valve 19 and the air motor 12, thus stopping the washing action.

The cam 25 is connected to the gear reducer shaft 58 in such a position that the masks held on the mask holder will be held up out of the washing solution when the washing cycle ends and the machine stops. Stopping the masks in this position facilitates loading and unloading and permits the mask to drain and dry after it has been washed. The cam may be designed so that the masks are lifted out of the solution at the end of each cycle. Therefore, the mask re-entering the solution will cause considerably more agitation of the fluid.

The clamp for attaching the mask to the mask holder 39 is shown in FIG. 5. A mask 86 is attached to a plate 87 in a well known manner such as by means of soldering or brazing. One side edge is disposed on the cross bar 59 and lugs 83 are urged against the upper surface by toggle clamps 89. The toggle clamps 89 are pivoted at 91 to a bracket which is in turn fixed to the cross bar 59. Handles 92 are swingably connected to the bracket 90. A surface between the legs of the handles 92 overlies the toggle clamps 89 and urges them downwardly when the handles 92 are in the position shown. This forces the lugs 88 down to clamp the plate 87 to the bar 59. To release the plate 87, the handles 92 are swung rearwardly and they move from over the toggle clamps 89, allowing the toggle clamps 89 to swing upwardly.

In FIG. 6, another embodiment of the invention is shown. A machine is similar to the machine shown in the other embodiment of the invention and it has a mask holder 139 thereon. The mask holder 139 is attached to a shaft 138 similar to the shaft 30 in FIG. 2 and the opposite end of the mask holder is attached to a shaft 158. A gear 131 is fixed to the shaft 158 and rotates therewith. The gear 131 has external teeth which mesh with the teeth on a rack 148. The rack 148 is held in engagement with the gear 131 by a roller 149. The roller 149 is rotatably mounted on an end 142 of the mask washer. The end of the rack 148 opposite the toothed end is pivotally attached at 143 to a wheel 144 on the shaft of a motor 145.

The motor 145 may be driven by electricity or it could be an air motor or any other suitable prime mover and since the point 143 is offset from a shaft 146 of the motor 145, as the motor rotates, the rack 148 oscillates and causes the gear 131 to rotate first in one direction and then in the other. The motor 145 gives the rack 148 a sinusoidal velocity. Therefore, the mask holder 139 will bring the mask attached thereto to a stop when the mask rises out of the liquid in the tank and will return the mask to the liquid at a low velocity but will move it through the liquid at an increasingly high velocity to emerge at a low velocity. Therefore, since the masks move slowly as they leave the liquid and as they return to the liquid, the liquid will not be splashed, yet the velocity of movement of liquid over the mask will be rapid as the mask is moved through it.

The foregoing specification sets forth the invention in its preferred practical forms but the structure shown is capable of modification within a range of equivalents without departing from the invention which is to be understood is broadly novel as is commensurate with the appended claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A mask washer comprising a tank having an open top and adapted to contain solvent, a mask support in said tank supported to rotate around a horizontal axis, means to attach a mask to said mask support in spaced relation to the axis of rotation thereof, a motor, means connecting said motor to a shaft to drive said shaft, a fluid circuit to conduct driving fluid to said motor, a cam attached to said mask support, spaced valves supported on said mask washer, followers on said valves engaging said cam, each said follower being actuated by said cam when said cam is rotated to a predetermined position actuating said spaced valves, means actuated by said spaced valves to reverse said motor whereby said mask support is driven first in one direction and then in the other, moving said mask support into said solvent and out of said solvent, stopping it out of said solvent and then moving it into said solvent, a timer valve controlling the time during which fluid is connected to said motor, and means to actuate said timer valve.

2. The mask washer recited in claim 1 wherein said means actuating said valves to reverse said motor comprises a first valve, a second valve, and a third valve, said timer valve actuating said first valve to connect fluid to actuating means on said second valve, said second valve, when actuated by said timer valve, connecting fluid to said third valve, said third valve selectively connecting said fluid to said motor to drive it in said first and then said second direction, said spaced valves being connected to said second and third valves whereby said second and third valves are actuated.

3. The mask washer recited in claim ,2 wherein said second and third valves are pilot controlled valves, one said spaced valve actuating one pilot control on said second valve and said third valve when said one spaced valve is held open by said cam, the other said spaced valve, when actuated by said cam, actuating the other pilot on said third valve.

4. A machine for processing masks comprising a tank adapted to contain solvent, a mask support in said tank, a motor driving said mask support, a control for said motor, said control comprising a fluid circuit to conduct driving fluid to said motor, a cam attached to said mask support, spaced valves supported on said machine, followers on said valves engaging said cam, each said follower being actuated by said cam when said cam is rotated to a predetermined position actuating said spaced valves, means actuated by said spaced valves to reverse said motor whereby said mask support is driven first in one direction and then in the other, and a timer valve controlling the time during which fluid is connected to said motor, and means to actuate said timer valve, moving said mask support into said solvent and out of said solvent, stopping it out of said solvent and then moving it into said solvent.

5. The machine recited in claim 4 wherein said means actuating said valves to reverse said motor comprises a first, a second, and a third valve, said timer valve actuating said first valve to connect fluid to actuating means on said second valve, said second valve, when actuated by said timer valve, connecting fluid to said third valve, said third valve selectively connecting said fluid to said motor to drive it in said first and then said second direction, said spaced valves being connected to said second and third valves whereby said second and third valves are actuated.

6. The machine recited in claim 5 wherein said second and third valves are pilot controlled valves, one said spaced valve actuating one pilot control on said second and said third valve when said one spaced valve is held open by said cam, the other said spaced valve, when actuated by said cam, actuating the other pilot on said third valve.

7. A mask washer and a driving mechanism therefor comprising a tank adapted to contain solvent a rotatable means for attaching a mask, a cam on said rotatable means, a motor driving said rotatable means, pilot means engaging said cam, a reversing valve connecting a source of driving fluid to said motor, said reversing valve being reversible to reverse the flow of said fluid to said motor to reverse said motor, pilot means on said reversing valve for reversing it, and valve means actuated by said pilot means on said cam and actuating said pilot means on said reversing valve, moving said rotatable means into said solvent and out of said solvent, stopping it out of said solvent and then moving it into said solvent.

References Cited in the file of this patent UNITED STATES PATENTS 261,548 reen July 25, 1882 581,685 Becht May 4, 1897 740,793 Barrick Oct. 6, 1903 1,382,117 Opocensky June 21, 1921 1,511,648 Wennerblad Oct. 14, 1924 2,074,599 Todd Mar. 23, 1937 2,519,259 Liebman Aug. 15, 1950 2,989,061 Winkler June 20, 1961 

1. A MASK WASHER COMPRISING A TANK HAVING AN OPEN TOP AND ADAPTED TO CONTAIN SOLVENT, A MASK SUPPORT IN SAID TANK SUPPORTED TO ROTATE AROUND A HORIZONTAL AXIS, MEANS TO ATTACH A MASK TO SAID MASK SUPPORT IN SPACED RELATION TO THE AXIS OF ROTATION THEREOF, A MOTOR, MEANS CONNECTING SAID MOTOR TO A SHAFT TO DRIVE SAID SHAFT, A FLUID CIRCUIT TO CONDUCT DRIVING FLUID TO SAID MOTOR, A CAM ATTACHED TO SAID MASK WASHER, FOLLOWERS ON SAID VALVES PORTED ON SAID MASK WASHER, FOLLOWERS ON SAID VALVES ENGAGING SAID CAM, EACH SAID FOLLOWER BEING ON ACTUATED BY SAID CAM WHEN SAID CAM IS ROTATED TO A PREDETERMINED POSITION ACTUATING SAID SPACED VALVES, MEANS ACTUATED BY SAID SPACED VALVES TO REVERSE SAID MOTOR WHEREBY SAID MASK SUPPORT IS DRIVEN FIRST IN ONE DIRECTION AND THEN IN THE OTHER, MOVING SAID MASK SUPPORT INTO SAID SOLVENT AND OUT OF SAID SOLVENT, STOPPING IT OUT OF SAID SOLVENT AND THEN MOVING IT INTO SAID SOLVENT, A TIMER VALVE CONTROLLING THE TIME DURING WHICH FLUID IS CONNECTED TO SAID MOTOR, AND MEANS TO ACTUATE SAID TIMER VALVER. 